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Vancomycin-resistant Enterococcus spp. (VRE) were isolated from sewage and chicken feces but not from other animal fecal sources (dog, cow, and pig) or from surface waters tested. VRE from hospital wastewater were resistant to >20 g of vancomycin/ml and possessed the vanA gene. VRE from residential wastewater and chicken feces were resistant to 3 to 5 g of vancomycin/ml and possessed the vanC gene.Vancomycin resistance in Enterococcus species is becoming a major concern in clinical settings as the rate of occurrence of vancomycin-resistant Enterococcus spp. (VRE) implicated in disease increases. For example, by 1999 the incidence of VREmediated nosocomial infections in intensive care units had increased 43% from that of the period of 1994 to 1998 (23). Enterococcus faecalis and E. faecium are reported more frequently as etiological agents of disease than are other enterococci (14, 15), but other species, such as E. avium (25), occasionally cause disease.Several operons that mediate vancomycin resistance in Enterococcus spp. have been identified. Perhaps the most significant from an epidemiological standpoint is vanA-mediated vancomycin resistance, as these genes are carried on transposon Tn1546 (4) and confer inducible high-level resistance to vancomycin and teicoplanin (19). The chromosomally encoded phenotype mediated by the vanC gene is marked by low-level resistance to vancomycin (20) and is an intrinsic characteristic of E. gallinarum (11), E. casseliflavus, and E. flavescens (24).VRE that are resistant to high levels of vancomycin can be readily isolated from the feces of domestic animals in Europe (2, 10) and from humans with no exposure to hospitals (17, 31). There has been no report of high-level vancomycin resistance (Ͼ32 g/ml) in Enterococcus spp. from animal feces or from humans without hospital exposure in the United States. In spite of a 1997 call for the investigation of sources of VRE outside the health care setting in the United States (21), there are remarkably few publications containing such data (8). VRE that are intrinsically resistant to low levels of vancomycin, such as E. gallinarum, E. casseliflavus, and E. flavescens, have been isolated from bird feces (30), and E. gallinarum containing the vanC gene has been isolated from chickens and farm lagoons (8).As part of another study (18), our laboratory isolated thousands of fecal streptococci (a group that includes Enterococcus spp. and other group D Streptococcus spp.) from animal feces, wastewater, and surface waters. Some of these isolates were resistant to high levels (Ͼ32 g/ml) of vancomycin. In order to investigate the presence of VRE in wastewater, animal feces, and surface waters, all VRE were identified to the genus and species level.Isolation of vancomycin-resistant fecal streptococci. Fecal streptococcus isolates were obtained from the feces of cattle, chickens, dogs, pigs, and wild animals (birds and raccoons). Fecal streptococci were also isolated from wastewater samples collected at a central sewer lift station (designated LF)...

Aims: The accuracy of ribotyping and antibiotic resistance analysis (ARA) for prediction of sources of faecal bacterial pollution in an urban southern California watershed was determined using blinded proficiency samples. Methods and Results: Antibiotic resistance patterns and HindIII ribotypes of Escherichia coli (n ¼ 997), and antibiotic resistance patterns of Enterococcus spp. (n ¼ 3657) were used to construct libraries from sewage samples and from faeces of seagulls, dogs, cats, horses and humans within the watershed. The three libraries were analysed to determine the accuracy of host source prediction. The internal accuracy of the libraries (average rate of correct classification, ARCC) with six source categories was 44% for E. coli ARA, 69% for E. coli ribotyping and 48% for Enterococcus ARA. Each library's predictive ability towards isolates that were not part of the library was determined using a blinded proficiency panel of 97 E. coli and 99 Enterococcus isolates. Twenty-eight per cent (by ARA) and 27% (by ribotyping) of the E. coli proficiency isolates were assigned to the correct source category. Sixteen per cent were assigned to the same source category by both methods, and 6% were assigned to the correct category. Addition of 2480 E. coli isolates to the ARA library did not improve the ARCC or proficiency accuracy. In contrast, 45% of Enterococcus proficiency isolates were correctly identified by ARA. Conclusions: None of the methods performed well enough on the proficiency panel to be judged ready for application to environmental samples. Significance and Impact of the Study: Most microbial source tracking (MST) studies published have demonstrated library accuracy solely by the internal ARCC measurement. Low rates of correct classification for E. coli proficiency isolates compared with the ARCCs of the libraries indicate that testing of bacteria from samples that are not represented in the library, such as blinded proficiency samples, is necessary to accurately measure predictive ability. The library-based MST methods used in this study may not be suited for determination of the source(s) of faecal pollution in large, urban watersheds.

Aims:  Microbial water quality and possible human sources of faecal pollution were assessed in a Florida estuary that serves shellfishing and recreational activities. Methods and Results:  Indicator organisms (IO), including faecal coliforms, Escherichia coli and enterococci, were quantified from marine and river waters, sediments and oysters. Florida recreational water standards were infrequently exceeded (6–10% of samples); however, shellfishing standards were more frequently exceeded (28%). IO concentrations in oysters and overlaying waters were significantly correlated, but oyster and sediment IO concentrations were uncorrelated. The human‐associated esp gene of Enterococcus faecium was detected in marine and fresh waters at sites with suspected human sewage contamination. Lagrangian drifters, used to determine the pathways of bacterial transport and deposition, suggested that sediment deposition from the Ochlockonee River contributes to frequent detection of esp at a Gulf of Mexico beach. Conclusions:  These data indicate that human faecal pollution affects water quality in Wakulla County and that local topography and hydrology play a role in bacterial transport and deposition. Significance and Impact of the Study:  A combination of IO enumeration, microbial source tracking methods and regional hydrological study can reliably inform regulatory agencies of IO sources, improving risk assessment and pollution mitigation in impaired waters.